1. Technical Field
The present invention relates to a method of manufacturing a liquid jet head which jets liquid droplets onto a recording medium to perform recording, a liquid jet head, and a liquid jet apparatus.
2. Related Art
In recent years, there has been used a liquid jet head of an ink jet system which ejects ink droplets onto, for example, recording paper to record characters or figures thereon, or ejects a liquid material onto the surface of an element substrate to form a functional thin film thereon. In this ink jet system, liquid such as ink and a liquid material is guided from a liquid tank into a channel through a supply tube, and pressure is applied to the liquid filled in the channel to thereby eject the liquid as liquid droplets from a nozzle which communicates with the channel. In the ejection of liquid droplets, characters or figures are recorded, or a functional thin film having a predetermined shape or a three-dimensional structure is formed by moving the liquid jet head or a recording medium.
JP 2002-210955 A describes this type of liquid jet head. FIG. 9 is a schematic cross-sectional view of the liquid jet head (FIG. 2 of JP 2002-210955 A). The liquid jet head is provided with a head chip 110 which ejects ink droplets and an ink manifold member 120 which supplies ink to the head chip 110. The head chip 110 is provided with a channel portion 115. The channel portion 115 is surrounded by two drive walls (not illustrated) each of which is composed of a piezoelectric body, a lower substrate 111, an upper substrate 113, a back plate 119, and a nozzle plate 118. The ink manifold member 120 is provided with an ink flow path 121 and an upper face holding portion 122a. The ink manifold member 120 is bonded to the back plate 119 of the head chip 110 with the upper face holding portion 122a covering the upper substrate 113 of the head chip 110. Ink flowing into the ink flow path 121 is supplied to the channel portion 115 through an ink introduction port 119a of the back plate 119. When the drive walls of the channel portion 115 are driven, ink droplets are ejected through a nozzle hole 118a. 
A conductive member 117b is disposed on the upper substrate 113. The conductive member 117b penetrates the upper substrate 113 in the thickness direction thereof. The conductive member 117b is electrically connected to drive electrodes disposed on the drive walls which drive the channel portion 115. The upper face holding portion 122a is provided with an electrode 123 which penetrates the upper face holding portion 122a in the thickness direction thereof. The electrode 123 is disposed at a position corresponding to the conductive member 117b. The electrode 123 is electrically connected to the conductive member 117b through an electrode 117c which is formed on the upper surface of the upper substrate 113. Further, the electrode 123 is electrically connected to an electrode 124 which is formed on an upper surface 120a of the ink manifold member 120 so as to be extracted to a back surface 120b of the ink manifold member 120. Thus, a drive waveform for driving the drive walls is input to the electrode 124 on the back surface 120b, and supplied to the drive electrodes on the drive walls through the electrode 123 disposed on the upper face holding portion 122a and the conductive member 117b disposed on the upper substrate 113.
JP 7-178903 A describes an ink jet apparatus which includes ejection grooves which are filled with ink and non-ejection grooves which are not filled with ink, the ejection grooves and the non-ejection grooves being alternately arrayed. The ink jet apparatus is provided with a piezoelectric ceramic plate in which the ejection grooves and the non-ejection grooves are alternately formed on the upper surface thereof and a cover plate which is bonded to the piezoelectric ceramic plate to block upper surface openings of both the ejection grooves and the non-ejection grooves. The ejection grooves do not penetrate the piezoelectric ceramic plate and are thus blocked on both the upper and lower sides thereof. The non-ejection grooves penetrate the piezoelectric ceramic plate from the upper surface through the lower surface thereof. Thus, the non-ejection grooves are blocked by the cover plate on the upper side thereof and open on the lower surface of the piezoelectric ceramic plate on the lower side thereof. Metal electrodes are formed on opposite side surfaces of each of the ejection grooves from the upper surface up to half the depth of the groove. Metal electrodes are formed on opposite side surfaces of each of the non-ejection grooves, the lower surface of the cover plate, the lower surface facing the piezoelectric ceramic plate, and the entire lower surface of the piezoelectric ceramic plate. Thus, all the metal electrodes formed on the non-ejection grooves are electrically connected to each other. The metal electrodes of the non-ejection grooves are connected to GND. Further, a drive waveform is applied to the meatal electrodes of the ejection grooves to drive partition walls between the ejection grooves and the non-ejection grooves, thereby ejecting ink droplets from nozzles communicating with the respective ejection grooves.